Remove unnecessary file

tool/lrama/lib/lrama/warning.rb

@@ -1,25 +0,0 @@
-module Lrama
-  class Warning
-    attr_reader :errors, :warns
-
-    def initialize(out = STDERR)
-      @out = out
-      @errors = []
-      @warns = []
-    end
-
-    def error(message)
-      @out << message << "\n"
-      @errors << message
-    end
-
-    def warn(message)
-      @out << message << "\n"
-      @warns << message
-    end
-
-    def has_error?
-      !@errors.empty?
-    end
-  end
-end